Trace Element Distribution of Middle-Upper Triassic Carbonate-Hosted Lead-Zinc Mineralizations: The Example of the Raibl Deposit (Eastern Alps, Italy)

Abstract

The Raibl deposit (northern Italy) was an economically important carbonate-hosted, fissure-controlled lead-zinc concentration in the Alpine-type Triassic. Trace element analysis of 111 sulphide-rich sampIes, representing the whole deposit, has revealed a zonal distribution for Ge, Cd, Ga, Tl, As, Sb. The considered trace elements are linked to sphalerite (Ge-Cd-Ga association) and to specific Pb-As-(Sb)-S phases (Tl-As-Sb association). The obtained results suggest that Ge, Tl and As are prominent trace metals in the northern part of the deposit, whereas to the south Cd, and to a lesserextent Sb and Ga, increase conspicuously. The resulting zones partly coincide with distinctive geologieal and paragenetic features. This overlapping suggests a possible genetic connection between the ore geochemistry and the tectonic and deposi-tional evolution of the deposit.